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linux-next/drivers/ide/ide-floppy_ioctl.c
Linus Torvalds 07bd3f4731 ide-floppy: allocate only toplevel packet commands
This makes the top-level function just allocate a single pc entry, and then
pass it down as a pointer to all the helper functions that also need one
of those "struct ide_atapi_pc" things. As far as I can tell, the use of
these things never overlaps each other, BUT I DID NOT CHECK VERY CLOSELY!

So I'm not guaranteeing this is correct, and I don't have the hardware. It
would be good for somebody who knows the code more, and has the hardware,
could please test this?

With this, ide-floppy still has fairly big stack usage, but instead of

	idefloppy_ioctl [vmlinux]:              1208
	ide_floppy_get_capacity [vmlinux]:      872
	idefloppy_release [vmlinux]:            408
	idefloppy_open [vmlinux]:               408

where those two first ones are at the very top of the list of stack users
for me, it's now

	ide_floppy_get_capacity [vmlinux]:           404
	ide_floppy_ioctl [vmlinux]:                  364

ie they are still high, but they are no longer at the top.

Borislav: Since ide_floppy_get_capacity is passed as a function pointer to other
parts of the kernel (e.g., block layer) we need that ide_atapi_pc to be created
on stack. Also, redid stack users numbers above. The two functions missing from
Linus' original 'make stackusage' output are due to ide being
rewritten/reorganized atm.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
2009-01-02 16:12:51 +01:00

292 lines
6.9 KiB
C

/*
* ide-floppy IOCTLs handling.
*/
#include <linux/kernel.h>
#include <linux/ide.h>
#include <linux/cdrom.h>
#include <asm/unaligned.h>
#include <scsi/scsi_ioctl.h>
#include "ide-floppy.h"
/*
* Obtain the list of formattable capacities.
* Very similar to ide_floppy_get_capacity, except that we push the capacity
* descriptors to userland, instead of our own structures.
*
* Userland gives us the following structure:
*
* struct idefloppy_format_capacities {
* int nformats;
* struct {
* int nblocks;
* int blocksize;
* } formats[];
* };
*
* userland initializes nformats to the number of allocated formats[] records.
* On exit we set nformats to the number of records we've actually initialized.
*/
static int ide_floppy_get_format_capacities(ide_drive_t *drive,
struct ide_atapi_pc *pc,
int __user *arg)
{
struct ide_disk_obj *floppy = drive->driver_data;
u8 header_len, desc_cnt;
int i, blocks, length, u_array_size, u_index;
int __user *argp;
if (get_user(u_array_size, arg))
return -EFAULT;
if (u_array_size <= 0)
return -EINVAL;
ide_floppy_create_read_capacity_cmd(pc);
if (ide_queue_pc_tail(drive, floppy->disk, pc)) {
printk(KERN_ERR "ide-floppy: Can't get floppy parameters\n");
return -EIO;
}
header_len = pc->buf[3];
desc_cnt = header_len / 8; /* capacity descriptor of 8 bytes */
u_index = 0;
argp = arg + 1;
/*
* We always skip the first capacity descriptor. That's the current
* capacity. We are interested in the remaining descriptors, the
* formattable capacities.
*/
for (i = 1; i < desc_cnt; i++) {
unsigned int desc_start = 4 + i*8;
if (u_index >= u_array_size)
break; /* User-supplied buffer too small */
blocks = be32_to_cpup((__be32 *)&pc->buf[desc_start]);
length = be16_to_cpup((__be16 *)&pc->buf[desc_start + 6]);
if (put_user(blocks, argp))
return -EFAULT;
++argp;
if (put_user(length, argp))
return -EFAULT;
++argp;
++u_index;
}
if (put_user(u_index, arg))
return -EFAULT;
return 0;
}
static void ide_floppy_create_format_unit_cmd(struct ide_atapi_pc *pc, int b,
int l, int flags)
{
ide_init_pc(pc);
pc->c[0] = GPCMD_FORMAT_UNIT;
pc->c[1] = 0x17;
memset(pc->buf, 0, 12);
pc->buf[1] = 0xA2;
/* Default format list header, u8 1: FOV/DCRT/IMM bits set */
if (flags & 1) /* Verify bit on... */
pc->buf[1] ^= 0x20; /* ... turn off DCRT bit */
pc->buf[3] = 8;
put_unaligned(cpu_to_be32(b), (unsigned int *)(&pc->buf[4]));
put_unaligned(cpu_to_be32(l), (unsigned int *)(&pc->buf[8]));
pc->buf_size = 12;
pc->flags |= PC_FLAG_WRITING;
}
static int ide_floppy_get_sfrp_bit(ide_drive_t *drive, struct ide_atapi_pc *pc)
{
struct ide_disk_obj *floppy = drive->driver_data;
drive->atapi_flags &= ~IDE_AFLAG_SRFP;
ide_floppy_create_mode_sense_cmd(pc, IDEFLOPPY_CAPABILITIES_PAGE);
pc->flags |= PC_FLAG_SUPPRESS_ERROR;
if (ide_queue_pc_tail(drive, floppy->disk, pc))
return 1;
if (pc->buf[8 + 2] & 0x40)
drive->atapi_flags |= IDE_AFLAG_SRFP;
return 0;
}
static int ide_floppy_format_unit(ide_drive_t *drive, struct ide_atapi_pc *pc,
int __user *arg)
{
struct ide_disk_obj *floppy = drive->driver_data;
int blocks, length, flags, err = 0;
if (floppy->openers > 1) {
/* Don't format if someone is using the disk */
drive->dev_flags &= ~IDE_DFLAG_FORMAT_IN_PROGRESS;
return -EBUSY;
}
drive->dev_flags |= IDE_DFLAG_FORMAT_IN_PROGRESS;
/*
* Send ATAPI_FORMAT_UNIT to the drive.
*
* Userland gives us the following structure:
*
* struct idefloppy_format_command {
* int nblocks;
* int blocksize;
* int flags;
* } ;
*
* flags is a bitmask, currently, the only defined flag is:
*
* 0x01 - verify media after format.
*/
if (get_user(blocks, arg) ||
get_user(length, arg+1) ||
get_user(flags, arg+2)) {
err = -EFAULT;
goto out;
}
ide_floppy_get_sfrp_bit(drive, pc);
ide_floppy_create_format_unit_cmd(pc, blocks, length, flags);
if (ide_queue_pc_tail(drive, floppy->disk, pc))
err = -EIO;
out:
if (err)
drive->dev_flags &= ~IDE_DFLAG_FORMAT_IN_PROGRESS;
return err;
}
/*
* Get ATAPI_FORMAT_UNIT progress indication.
*
* Userland gives a pointer to an int. The int is set to a progress
* indicator 0-65536, with 65536=100%.
*
* If the drive does not support format progress indication, we just check
* the dsc bit, and return either 0 or 65536.
*/
static int ide_floppy_get_format_progress(ide_drive_t *drive,
struct ide_atapi_pc *pc,
int __user *arg)
{
struct ide_disk_obj *floppy = drive->driver_data;
int progress_indication = 0x10000;
if (drive->atapi_flags & IDE_AFLAG_SRFP) {
ide_create_request_sense_cmd(drive, pc);
if (ide_queue_pc_tail(drive, floppy->disk, pc))
return -EIO;
if (floppy->sense_key == 2 &&
floppy->asc == 4 &&
floppy->ascq == 4)
progress_indication = floppy->progress_indication;
/* Else assume format_unit has finished, and we're at 0x10000 */
} else {
ide_hwif_t *hwif = drive->hwif;
unsigned long flags;
u8 stat;
local_irq_save(flags);
stat = hwif->tp_ops->read_status(hwif);
local_irq_restore(flags);
progress_indication = ((stat & ATA_DSC) == 0) ? 0 : 0x10000;
}
if (put_user(progress_indication, arg))
return -EFAULT;
return 0;
}
static int ide_floppy_lockdoor(ide_drive_t *drive, struct ide_atapi_pc *pc,
unsigned long arg, unsigned int cmd)
{
struct ide_disk_obj *floppy = drive->driver_data;
struct gendisk *disk = floppy->disk;
int prevent = (arg && cmd != CDROMEJECT) ? 1 : 0;
if (floppy->openers > 1)
return -EBUSY;
ide_set_media_lock(drive, disk, prevent);
if (cmd == CDROMEJECT)
ide_do_start_stop(drive, disk, 2);
return 0;
}
static int ide_floppy_format_ioctl(ide_drive_t *drive, struct ide_atapi_pc *pc,
fmode_t mode, unsigned int cmd,
void __user *argp)
{
switch (cmd) {
case IDEFLOPPY_IOCTL_FORMAT_SUPPORTED:
return 0;
case IDEFLOPPY_IOCTL_FORMAT_GET_CAPACITY:
return ide_floppy_get_format_capacities(drive, pc, argp);
case IDEFLOPPY_IOCTL_FORMAT_START:
if (!(mode & FMODE_WRITE))
return -EPERM;
return ide_floppy_format_unit(drive, pc, (int __user *)argp);
case IDEFLOPPY_IOCTL_FORMAT_GET_PROGRESS:
return ide_floppy_get_format_progress(drive, pc, argp);
default:
return -ENOTTY;
}
}
int ide_floppy_ioctl(ide_drive_t *drive, struct block_device *bdev,
fmode_t mode, unsigned int cmd, unsigned long arg)
{
struct ide_atapi_pc pc;
void __user *argp = (void __user *)arg;
int err;
if (cmd == CDROMEJECT || cmd == CDROM_LOCKDOOR)
return ide_floppy_lockdoor(drive, &pc, arg, cmd);
err = ide_floppy_format_ioctl(drive, &pc, mode, cmd, argp);
if (err != -ENOTTY)
return err;
/*
* skip SCSI_IOCTL_SEND_COMMAND (deprecated)
* and CDROM_SEND_PACKET (legacy) ioctls
*/
if (cmd != CDROM_SEND_PACKET && cmd != SCSI_IOCTL_SEND_COMMAND)
err = scsi_cmd_ioctl(bdev->bd_disk->queue, bdev->bd_disk,
mode, cmd, argp);
if (err == -ENOTTY)
err = generic_ide_ioctl(drive, bdev, cmd, arg);
return err;
}